Universal Booking ProtocolStandardized booking for AI agents

An open-source framework defining a 6-state booking lifecycle with fencing tokens, exposed over REST, MCP, and A2A transports.

6-State Lifecycle

Deterministic state machine — Available, Held, Negotiating, Pending, Confirmed, Fulfilled — with fencing tokens for concurrency control.

Built for LLM tool-use. Expose booking operations as MCP tools for Claude, GPT, and Cursor, or as A2A tasks for multi-agent coordination.

Same booking engine exposed over REST (Hono), MCP (stdio + SSE), and A2A (JSON-RPC 2.0). Pick one or run all three.

Distributed locks, monotonic fencing tokens, and idempotency keys ensure exactly-once semantics even under high contention.

Pluggable domain extensions for hospitality, healthcare, dining, and more. The protocol provides hooks — extensions own the validation rules.

Beckn-style multicast search across registered providers. Agents discover services without knowing individual provider URLs.